This invention relates generally to refrigerators and, more particularly, relates to an upright rear vertical wall extension for slide out refrigerator shelves, wherein the upright wall extension secures to the rear of a refrigerator shelf to prevent items stored on the refrigerator shelf from falling off the back side of the shelf as the shelf slides.
Typical refrigerator shelves include a glass plate with steel side support plates, overmolded with plastic, such as polypropylene. The molded perimeter shelf edge is a signature feature of the shelf, which may require separate, and costly, shelf molds, or sacrifice distinctiveness.
Refrigerator shelves are known to include an extended rear vertical wall. Such extended vertical walls may be molded or otherwise incorporated into the shelf design. Alternatively, the extended vertical walls may be separate pieces that clip or snap fit to the shelf assemblies.
Molded walls are short in height, due to molding limitations. More particularly, wall height affects manufacturing by complicating the design of the tooling and the process of molding shelves. Design of injection molds anticipates the cooling characteristics (shrink) of the molded part; unanticipated shrink distorts the expected final geometry. Influenced by the non-shrinking glass and the non-shrinking steel components and by their opposing orientations, the front and rear edges shrink differently than the sides of the injection-molded shelf. Consequently, the shrink characteristics of the molded shelf edges are inherently difficult to predict. Increasing the edge (wall) height exacerbates the difficulty of predicting and controlling the shrink (final geometry) of the molded shelf. Greater height affects the shelf cost, adding volume to the molds and adding time and variability to the process.
Another disadvantage of many of the prior art refrigerator shelf assemblies is that the extended vertical wall is not sufficiently tall enough to prevent items placed on the shelf from toppling over the back edge. U.S. Pat. No. 5,769,520 to Jun discloses a refrigerator shelf with a short molded back bracket. This molded back bracket only rises a small distance in height and will not restrain an item placed on the shelf, particularly a larger item, from toppling off the back edge of the shelf. U.S. Pat. No. 5,406,894 to Herrmann discloses an optional rear trim piece that also only rises a fraction of an inch in height and does not prevent items placed on the shelf from toppling off the back edge of the shelf.
Another disadvantage of many of the prior art refrigerator shelf assemblies is that the extended vertical wall is not a separate piece or is integral to the shelf brackets such that the extended vertical wall cannot be removed by the user. The molded back bracket disclosed in Jun primarily serves the function of securing the shelf to the back wall of the refrigerator. This molded back bracket is essential to the structure of the shelf assembly and cannot be removed or separated from the shelf. U.S. Pat. No. 4,923,260 to Poulsen discloses a rear retainer that clips onto the shelf brackets and retains the glass shelf. This rear retainer is integral to the shelf design and cannot be removed from the shelf assembly without compromising the structural integrity of the design. U.S. Pat. No. 3,912,085 to Cooke discloses a retaining clip with a vertical flange. The primary function of the retaining clip is to maintain the shelf in the frame. The retaining clip cannot be removed from the shelf assembly without compromising the structural integrity of the design.
Still another disadvantage of many of the prior art refrigerator shelf assemblies is that the extended vertical wall does not detach easily from the shelf. U.S. Pat. No. 4,736,997 to Besore discloses a reflector that snap fits onto the rear edge of the shelf. This reflector snaps tightly over the rear horizontal support member and cannot be easily removed. Further, because the primary function of this reflector is to hold the components at the rear of the shelf assembly together, the reflector cannot be removed without compromising the structural integrity of the shelf design.
Accordingly, a primary objective of the present invention is the provision of an upright rear wall extension for a slide-out refrigerator shelf that is separate and independent of the shelf and can be quickly and easily installed and removed.
Another objective of the present invention is the provision of an upright rear wall extension for a slide-out refrigerator shelf that is sufficiently tall and strong enough to prevent items placed on the shelf from toppling off the back of the shelf as the shelf slides.
Another objective of the present invention is the provision of an extended upright wall for the rear of a refrigerator shelf wherein the wall is injection molded.
A further objective of the present invention is the provision of an upright rear wall extension for a refrigerator shelf that utilizes a minimum of parts and is easy and inexpensive to manufacture, and durable in use.
These and other objectives will become apparent from the following specification and claims.